This application is for a two year study to adapt and evaluate the efficacy of a HIV prevention curriculum for 7th grade in-school Liberian youths, ages 14-16 years. The proposed intervention draws on an evidence-based curriculum, Making Proud Choices (Jemmott et al., 1998) that is currently being adapted in other Sub-Saharan African countries (e.g., Ghana, Kenya, South Africa, Swaziland, Liberia, etc.). The proposed study has three aims: (1) Adapt an evidence-based HIV prevention program, designed for community settings in the US, to be delivered in school classrooms in Liberia;(2) Evaluate the impact of the HIV prevention intervention on proximal and primary outcomes including delay sexual initiation, increasing condom use and changes in proximal variables including attitudes, intentions and self efficacy;and (3) Assess the characteristics of program implementation fidelity and its relationship to changes in behavioral outcomes. During the first eight months of the proposed two-year study, we will adapt this community-based curriculum to school-based settings and contexts within Liberia. Members of community-based organizations, health educators, school administrators and 7th-grade students will provide data to guide the integration and cultural adaptation of the curriculum through focus groups and one-on-one key informant interviews. Over the next 16 months we will conduct a cohort study to assess the impact of this adapted curriculum on changing sexual risk behaviors using a randomized controlled group design with schools as the restricted assignment unit. Four matched pairs of junior high schools will be randomly assigned to either an HIV prevention intervention or a comparison general health condition to assess the impact of the intervention on increasing condom use and delaying the initiation of sexual intercourse among Liberian youth (n=800). We will also assess the fidelity of curriculum implementation and its impact on behavioral outcomes. Through rigorous evaluation of the adapted HIV prevention curriculum, we hope to reduce sexual risk behaviors of in-school youth. By assessing the curriculum fidelity and its impact on behavioral outcomes, we will advance the field's understanding of the relationship of implementation fidelity and behavior change in resource deprived environments. Working with our Liberian investigators to implement and evaluate this intervention, we expect to continually build the social and behavioral research capacities of Liberian researchers and their research institutions. PUBLIC HEALTH RELEVANCE The cultural adaptation of an evidence based HIV prevention intervention for in-school Liberian youth and the assessment of its efficacy at reducing sexual risk behaviors will provide Liberian schools with an evidence based program to model and disseminate. Our assessment of curriculum fidelity and its impact on behavioral outcomes will advance the HIV prevention field by providing a more nuanced understanding of the relationship between implementation fidelity and behavior changes in resource deprived environments. Working with our Liberian investigators to implement and evaluate this intervention, we expect to continually build the social and behavioral research capacities of Liberian researchers and their research institutions.